As is known, mounting assemblies for high-power semiconductive controlled rectifiers require the use of heat sinks to carry away the heat generated during the power conversion process. In the usual case, the heat sinks are finned and of relatively large size. Furthermore, prior art assemblies for semiconductive controlled rectifiers usually require at least two heat sinks on opposite sides of one or more semiconductors.
The present invention is particularly adapted for use with press-pack or disc-type semiconductive controlled rectifiers. As is known, such rectifiers consist of a flat semiconductor assembly sandwiched between thin circular sheets of electrical conducting material and surrounded by a ring-shaped ceramic insulator which is bonded to the two circular sheets to form a hermetic seal. The thin circular sheets of electrical conducting material comprise the anode and cathode, respectively, of the rectifier. When mounting press-pack semiconductive controlled rectifiers of this type on heat sinks, it is necessary to provide a specific value of compressive force between the rectifier and the heat sink over the complete contact surface on opposite sides of the disc-shaped rectifier to insure good heat transfer as well as a good electrical connection. It is also desirable to thermally connect heat sinks to both sides of the rectifier to carry away the heat generated in the power conversion process and to obtain maximum utilization of the device parameters.
Since the circular electrical sheets of conducting material on opposite sides of the rectifier, comprising the anode and cathode connections, are not ordinarily parallel, some means must be provided to allow for surface alignment. This has been achieved in the past by a number of different spring devices which must transmit the spring pressure to the rectifiers and clamp the same between the two heat sink surfaces. Generally, there is a separate spring for each rectifier, along with a pivot point element or bellows arranged for each rectifier-heat sink configuration. As a result, when several press-pack semiconductive rectifiers are interconnected to provide alternating current or direct current outputs, the mechanical construction, electrical insulation, spacing and interconnecting wires become very elaborate and bulky, the heat sinks usually comprising large finned radiators on opposite sides of the rectifiers as described above.